A DNA test for fruit flesh color in tetraploid sour cherry (Prunus cerasus L.)

Fruit flesh color in tetraploid sour cherry (Prunus cerasus) is an important market-driven trait in the USA where the fruit from the dominant cultivar has brilliant red skin but clear/yellow flesh. This brilliant red color in the processed products differentiates products from sour cherries grown in the USA compared to those in Europe where the cultivars predominantly have dark purple-red flesh. In sweet cherry (P. avium), red skin and flesh colors were shown to be controlled by a major MYB10-associated locus. Sour cherry, which is derived from sweet cherry and ground cherry (P. fruticosa), also exhibits a range of flesh colors, but the genetic control of flesh color is not known. Our objectives were to test the hypothesis that the MYB10 locus controls flesh color in sour cherry and develop a predictive DNA test for dark purple-red flesh color. Pedigree-linked sour cherry plant materials were phenotyped for flesh color. Thirteen haplotypes for the sour cherry MYB10 region were distinguished based on markers scored from the use of the cherry 6K Infinium (R) II SNP array. Six haplotypes were significantly associated with variation in flesh color, supporting a role for MYB10 in controlling flesh color variation in sour cherry. A simple sequence repeat primer pair, designed from the peach genome sequence near MYB10, amplified a fragment that uniquely identified the haplotype that was associated with the darkest purple-red flesh color. This marker can be used for marker-assisted breeding to identify individuals that are predicted to have dark purple-red flesh.